From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailout2.hostsharing.net (mailout2.hostsharing.net [83.223.78.233]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 800203E0C66; Tue, 24 Mar 2026 10:09:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=83.223.78.233 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774346983; cv=none; b=oSptlbp1g93kqOadjbzHarPZLsnypDATdMTbzxUe0FWPOYtQnLd2MfzQspFMuM4iZvBFPL2eUDUKEwIOzLa45v0qT7zYSOdFrLiLY7WchycY9Ii2K6n7KgdszH6kGKzPvbD0NajA5zKD1IMaPWqMvPjsVjxsy7JS/4gAKq2NcsE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774346983; c=relaxed/simple; bh=pmsrmIHgYeHFG0kURoZevA5M15R4F0uqCB8leN/RxYM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ijqcXKQJ+CaDTLlAvIuLwOxp8vNXrFUjlrug+t5ZXExGm1AxH8YccGIQqyI+hIp5Qy8e0VcbH28szeHXWn/ENRB3DuFb5buHpEJops86iIrNWOiUvcZ0qUduOhpdUuYv2w0pv+lFYgVsQiJZH5MTwuB9ZmUuqLp6Qh7e7kMLUgQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=wunner.de; spf=pass smtp.mailfrom=wunner.de; arc=none smtp.client-ip=83.223.78.233 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=wunner.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=wunner.de Received: from h08.hostsharing.net (h08.hostsharing.net [IPv6:2a01:37:1000::53df:5f1c:0]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384 client-signature ECDSA (secp384r1) client-digest SHA384) (Client CN "*.hostsharing.net", Issuer "GlobalSign GCC R6 AlphaSSL CA 2025" (verified OK)) by mailout2.hostsharing.net (Postfix) with ESMTPS id EE43610632; Tue, 24 Mar 2026 11:09:35 +0100 (CET) Received: by h08.hostsharing.net (Postfix, from userid 100393) id DB61D602F6DA; Tue, 24 Mar 2026 11:09:35 +0100 (CET) Date: Tue, 24 Mar 2026 11:09:35 +0100 From: Lukas Wunner To: Maciej Grochowski Cc: Bjorn Helgaas , Jonathan Corbet , linux-pci@vger.kernel.org, linux-doc@vger.kernel.org, Mika Westerberg , Ilpo Jarvinen , Kai-Heng Feng Subject: Re: [PATCH] Documentation: PCI: Document decoding of TLP Header in AER messages Message-ID: References: <20260323165038.GA830530@bhelgaas> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Tue, Mar 24, 2026 at 05:53:30AM +0000, mx2pg@pm.me wrote: > One thing worth calling out: starting with PCIe 6.0, Flit Mode is > mandatory at 64.0 GT/s and supported at all PCIe link speeds, so a > Flit-capable PCIe 6.x link may operate below 64.0 GT/s and still be > in Flit Mode. The raw TLP Header bytes do not encode the framing — > the same four bytes decode to entirely different packet types in > non-Flit vs Flit framing. The negotiated mode can be read from the > Flit Mode Status bit in Link Status 2, or via lspci -vv on a recent > pciutils build. Thanks Maciej for chiming in. Ilpo (who is cc'ed) amended the kernel last year with commit 7e077e6707b3 ("PCI/ERR: Handle TLP Log in Flit mode") to suffix the hexdump with " (Flit)" in Flit Mode: https://git.kernel.org/linus/7e077e6707b3 Any chance you could amend tlp-tool to auto-detect Flit Mode if the suffix is present? As an aside: Prior to that, commit f68ea779d98a ("PCI: Add pcie_print_tlp_log() to print TLP Header and Prefix Log") changed the log message to prefix each dword with "0x". But I tested it and it seems that tlp-tool groks both the old and the new format without any code change: https://git.kernel.org/linus/f68ea779d98a But we need to be careful going forward not to break user space tooling that might rely on the syntax. Thanks, Lukas